5 ms·

Lunar mystery solved by recovery of lost Apollo mission tapes

102 points by curtis 8y ago

viridian 8y ago
This is the experiment in question, for those curious: https://www.lpi.usra.edu/lunar/missions/apollo/apollo_17/experiments/hf/ https://www.lpi.usra.edu/lunar/missions/apollo/apollo_17/exp... The article outlines some of the details as well, but it was lacking in depth, which can be found in the experiment results and details links in the page above.
- acqq 8y ago
  More background on the device: https://en.m.wikipedia.org/wiki/Apollo_Lunar_Surface_Experiments_Package https://en.m.wikipedia.org/wiki/Apollo_Lunar_Surface_Experim... Apparently just the plutonium in the power supply of only one of these units would cost today some 20 million USD. https://news.ycombinator.com/item?id=17492902 https://news.ycombinator.com/item?id=17492902
_rpd 8y ago
Here's the paper ... Examination of the Long‐Term Subsurface Warming Observed at the Apollo 15 and 17 Sites Utilizing the Newly Restored Heat Flow Experiment Data From 1975 to 1977 > The Apollo heat flow experiment (HFE) was conducted at landing sites 15 and 17. On Apollo 15, surface and subsurface temperatures were monitored from July 1971 to January 1977. On Apollo 17, monitoring took place from December 1972 to September 1977. The investigators involved in the HFE examined and archived only data from the time of deployment to December 1974. The present authors recovered and restored major portions of the previously unarchived HFE data from January 1975 through September 1977. The HFE investigators noted that temperature of the regolith well below the reach of insolation cycles (~1 m) rose gradually through December 1974 at both sites. The restored data showed that the subsurface warming continued until the end of observations in 1977. Simultaneously, the thermal gradient decreased, because the warming was more pronounced at shallower depths. The present study has examined potential causes for the warming. Recently acquired images of the Lunar Reconnaissance Orbiter Camera over the two landing sites show that the regolith on the paths of the astronauts turned darker, lowering the albedo. We suggest that, as a result of the astronauts' activities, solar heat intake by the regolith increased slightly on average, and that resulted in the observed warming. Simple analytical heat conduction models with constant regolith thermal properties can show that an abrupt increase in surface temperature of 1.6 to 3.5 K at the time of probe deployment best duplicates the magnitude and the timing of the observed subsurface warmings at both Apollo sites. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JE005579 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018...
teh_infallible 8y ago
How do tapes like this get lost in the first place? I mean, if you were a startup funding this mission, and your CTO said, “Oops! I totally lost all that data from our multibillion dollar mission!” wouldn’t you fire them immediately?
- outworlder 8y ago
  Yes. Except the CTO is dead and his grandson is in charge. And oh, the original building is no longer there. Also, there's no more funding for storage. By the way, the computer systems are no longer compatible and the paper records have faded.
  - saalweachter 8y ago
    And your department is only concerned with future capabilities, historical records are someone else's job. And your company just pivoted from lunar exploration to lunar colonization, no, Mars exploration, no, space stations, no, space defense, no, Mars exploration again.
  - Johnny555 8y ago
    And data storage was a lot more expensive to maintain and keep track of. When you have a room full of 9" reel tapes with handwritten labels, it's hard to know what you're throwing away when you need more space. If you don't have the (again, probably handwritten) book that tells you what's on the tapes, then you probably just don't know what's there.
- azernik 8y ago
  In addition to outworlder's comment, note that data storage was a lot harder back then; these days we store them on a network-addressable server with automatic systems to transfer the data between different backups. Back then this was all manual and super error-prone.
  - hermitdev 8y ago
    Data transfer for some telescopes is still "analogue". It can be higher bandwidth to literally FedEx banks of hard drives than it is to transfer over the internet.
bigiain 8y ago
Anthropogenic Lunar Warming! (Humans are the worst...)
lucb1e 8y ago
Summary: "raw data on the temperature of the moon's surface, as well as a few meters below it, was transmitted from the probes and recorded on magnetic tapes". Some of the tapes were not correctly archived and were only recently found. The previously available tapes showed that "the moon unexpectedly rose in temperature by 1.8°F to 3.6°F near the probes. The possible reasons for this change were debated by planetary scientists for decades." Now with the new data, and because "researchers were also able to look at recently acquired images from the Lunar Reconnaissance Orbiter Camera over the two landing sites, [t]he only scenario that fits this type of warming is that the astronauts caused it. While they were driving[/walking] over the surface, [they] disturbed the moon's surface, which is covered in regolith, a layer of dust and debris. Images from the camera show that those paths were darker, which lowered their albedo, or ability to reflect the sun's light into space", thereby absorbing more heat.
- some_account 8y ago
  Right. Lost mission tapes. We are lucky they happened to appear. Super convenient, how those astronauts happened to double the surface temperature of the moon (oh, near the probes) by just standing there.
  - FreeFull 8y ago
    A change from 1.8 degrees Fahrenheit to 3.6 degrees Fahrenheit is not a doubling by any measure, because Fahrenheit is a relative temperature scale. 3.6F is 0.0039 times bigger than 1.8F
  - yason 8y ago
    It didn't double. It went up one degree in C or K, or +0.4% in K.
  - anticensor 8y ago
    Fahrenheit scale does not work like that.
  - eevilspock 8y ago
    So you believe Capricorn One was a documentary and 9/11 a government conspiracy?
msl09 8y ago
Does anyone know how effectively block that annoying video?
- SECProto 8y ago
  I have javascript disabled - I don't see a video. Rest of the article loads fine.
supermdguy 8y ago
I thought it was talking about these missing tapes: https://en.wikipedia.org/wiki/Apollo_11_missing_tapes https://en.wikipedia.org/wiki/Apollo_11_missing_tapes. That would have been amazing.
- deleted 8y ago
  [deleted]
- 8bitsrule 8y ago
  Me too. Some people spent -a lot- of time look for them. But, ya never know. Remember that warehouse they put Indiana's 'Lost Ark' in? Bet there are -a bunch- of those.
NVRM 8y ago
No. No need to loop around for 80 years. NO. Seriously. No way. STFU
- dang 8y ago
  If you can't or won't stop posting unsubstantive comments, as we've already asked, we're going to have to ban you. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
  - NVRM 8y ago
    https://en.wikipedia.org/wiki/Russell%27s_teapot https://en.wikipedia.org/wiki/Russell%27s_teapot

102 points by curtis 8y ago

This is the experiment in question, for those curious: https://www.lpi.usra.edu/lunar/missions/apollo/apollo_17/experiments/hf/ https://www.lpi.usra.edu/lunar/missions/apollo/apollo_17/exp... The article outlines some of the details as well, but it was lacking in depth, which can be found in the experiment results and details links in the page above.

acqq 8y ago
More background on the device: https://en.m.wikipedia.org/wiki/Apollo_Lunar_Surface_Experiments_Package https://en.m.wikipedia.org/wiki/Apollo_Lunar_Surface_Experim... Apparently just the plutonium in the power supply of only one of these units would cost today some 20 million USD. https://news.ycombinator.com/item?id=17492902 https://news.ycombinator.com/item?id=17492902

_rpd 8y ago

Here's the paper ... Examination of the Long‐Term Subsurface Warming Observed at the Apollo 15 and 17 Sites Utilizing the Newly Restored Heat Flow Experiment Data From 1975 to 1977 > The Apollo heat flow experiment (HFE) was conducted at landing sites 15 and 17. On Apollo 15, surface and subsurface temperatures were monitored from July 1971 to January 1977. On Apollo 17, monitoring took place from December 1972 to September 1977. The investigators involved in the HFE examined and archived only data from the time of deployment to December 1974. The present authors recovered and restored major portions of the previously unarchived HFE data from January 1975 through September 1977. The HFE investigators noted that temperature of the regolith well below the reach of insolation cycles (~1 m) rose gradually through December 1974 at both sites. The restored data showed that the subsurface warming continued until the end of observations in 1977. Simultaneously, the thermal gradient decreased, because the warming was more pronounced at shallower depths. The present study has examined potential causes for the warming. Recently acquired images of the Lunar Reconnaissance Orbiter Camera over the two landing sites show that the regolith on the paths of the astronauts turned darker, lowering the albedo. We suggest that, as a result of the astronauts' activities, solar heat intake by the regolith increased slightly on average, and that resulted in the observed warming. Simple analytical heat conduction models with constant regolith thermal properties can show that an abrupt increase in surface temperature of 1.6 to 3.5 K at the time of probe deployment best duplicates the magnitude and the timing of the observed subsurface warmings at both Apollo sites. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JE005579 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018...

teh_infallible 8y ago

How do tapes like this get lost in the first place? I mean, if you were a startup funding this mission, and your CTO said, “Oops! I totally lost all that data from our multibillion dollar mission!” wouldn’t you fire them immediately?

outworlder 8y ago
Yes. Except the CTO is dead and his grandson is in charge. And oh, the original building is no longer there. Also, there's no more funding for storage. By the way, the computer systems are no longer compatible and the paper records have faded.
- saalweachter 8y ago
  And your department is only concerned with future capabilities, historical records are someone else's job. And your company just pivoted from lunar exploration to lunar colonization, no, Mars exploration, no, space stations, no, space defense, no, Mars exploration again.
- Johnny555 8y ago
  And data storage was a lot more expensive to maintain and keep track of. When you have a room full of 9" reel tapes with handwritten labels, it's hard to know what you're throwing away when you need more space. If you don't have the (again, probably handwritten) book that tells you what's on the tapes, then you probably just don't know what's there.
azernik 8y ago
In addition to outworlder's comment, note that data storage was a lot harder back then; these days we store them on a network-addressable server with automatic systems to transfer the data between different backups. Back then this was all manual and super error-prone.
- hermitdev 8y ago
  Data transfer for some telescopes is still "analogue". It can be higher bandwidth to literally FedEx banks of hard drives than it is to transfer over the internet.

bigiain 8y ago

Anthropogenic Lunar Warming! (Humans are the worst...)

lucb1e 8y ago

Summary: "raw data on the temperature of the moon's surface, as well as a few meters below it, was transmitted from the probes and recorded on magnetic tapes". Some of the tapes were not correctly archived and were only recently found. The previously available tapes showed that "the moon unexpectedly rose in temperature by 1.8°F to 3.6°F near the probes. The possible reasons for this change were debated by planetary scientists for decades." Now with the new data, and because "researchers were also able to look at recently acquired images from the Lunar Reconnaissance Orbiter Camera over the two landing sites, [t]he only scenario that fits this type of warming is that the astronauts caused it. While they were driving[/walking] over the surface, [they] disturbed the moon's surface, which is covered in regolith, a layer of dust and debris. Images from the camera show that those paths were darker, which lowered their albedo, or ability to reflect the sun's light into space", thereby absorbing more heat.

some_account 8y ago
Right. Lost mission tapes. We are lucky they happened to appear. Super convenient, how those astronauts happened to double the surface temperature of the moon (oh, near the probes) by just standing there.
- FreeFull 8y ago
  A change from 1.8 degrees Fahrenheit to 3.6 degrees Fahrenheit is not a doubling by any measure, because Fahrenheit is a relative temperature scale. 3.6F is 0.0039 times bigger than 1.8F
- yason 8y ago
  It didn't double. It went up one degree in C or K, or +0.4% in K.
- anticensor 8y ago
  Fahrenheit scale does not work like that.
- eevilspock 8y ago
  So you believe Capricorn One was a documentary and 9/11 a government conspiracy?

msl09 8y ago

Does anyone know how effectively block that annoying video?

SECProto 8y ago
I have javascript disabled - I don't see a video. Rest of the article loads fine.

supermdguy 8y ago

I thought it was talking about these missing tapes: https://en.wikipedia.org/wiki/Apollo_11_missing_tapes https://en.wikipedia.org/wiki/Apollo_11_missing_tapes. That would have been amazing.

deleted 8y ago
[deleted]
8bitsrule 8y ago
Me too. Some people spent -a lot- of time look for them. But, ya never know. Remember that warehouse they put Indiana's 'Lost Ark' in? Bet there are -a bunch- of those.

NVRM 8y ago

No. No need to loop around for 80 years. NO. Seriously. No way. STFU

dang 8y ago
If you can't or won't stop posting unsubstantive comments, as we've already asked, we're going to have to ban you. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
- NVRM 8y ago
  https://en.wikipedia.org/wiki/Russell%27s_teapot https://en.wikipedia.org/wiki/Russell%27s_teapot